Loud-speaker horn



' Patented Aug. 28, 1928.

- UNITED STATE mm o. ransom, or nocxnonn, 'ILLlZNOIS,

rumors, a conro-zanrron or rumors.

FURNITURE COMPANY, OF ROCKFORD,

PATENT OFFICE.

ASSIGNOR TO ROCKFORD NOVELTY LoUn-srnmn norm.

Application filed April 9,

nection with phonograph reproducers.

The rincipal object is to provide a horn ,particu arly well adapted formounting in cabinets in the confined space usually available which hasbetter acoustic properties than those heretofore. provided.

With the foregoing object in view, the in. vention provides, in eliect,a horn within a horn in reversed relation so as to make a longer aircolumn available and thus increase the volume and produce truer tones,the arrangement also giving rise to a reflection of the sound from thesource whereby the echo is transmitted. A horn embodying these features,in addition to being simple and economical in construction, isthoroughly practical since it lends itself to installation in a varietyof cabinets by reason of its compactness and peculiarly adaptable form.

The invention is illustrated in the accom- I panying drawing,whereinwooden construction the bottom wall 11 F1 1 is a front view of ahorn embodying the novel features above referred to; and Fig. 2 is alongitudinal vertical section taken on the line 2-2 of Fig, 1 looking inthe direction of the arrows.

The horn of my invention, as illustrated by the present preferredembodiment, comprises a main horn or bell 5 and a secondary orn or hell6 preferably. within the same and reversed in direction with respectthereto. Both'horns are referably entirely of ibr best tone qualities.The main horn 5 is of a truncated form and has a relatively thick backwall 7 with side walls 8 and 9 and top and bottom walls 10 and 11extending in outwardly divergent relation thereto maintaining anapproximately rectangular section throughout, as shown. The secondarhorn 6 is built upon g the main horn with this wall forming one of theside wallsof the secondary horn. The term side, as

here used, and as used in the claims, should .be taken merely asdistinguishing from end walls such as the back wall 7 of the main horn 5or the back wall 12 of the secondary l6 horn 6. The back wall 12 of thesecondary horn 6-, it' be noted, is relatively thick as are also theside walls 13 and 14. The

From the description small end of the main horn me. Serial no. 160,752.

remaining wall 15, however, is comparatively thln. The purpose inroviding the side walls of the main horn oi appreciable thickness, aswell as the back and side walls of the secondary horn, is toeliminate'any tendency for any unpleasant vibrations being set up withinthe usual vibration periods of the sounds transmitted. The wall 15 ispro vlded comparatively thin so as not to restrict the sound passage andno objectional vibrat ons are apt to be set up at this source in view ofthe fact that all of the walls joinmg therewith are comparatively heavy.thus far it will be apparent that the area of the section of the soundpassage increases gradually from thesmallend of the secondaryhorn to thelarge end thereof and thence from the small end of the main horn to the.large end of the latter.. The large end of the secondary horn the sameWidth as the and, as will be apparent from the drawing, is ofapproximately half the hei ht.

By virtue of t e arrangement of the secondary horn 6 within the mainhorn 5 directed toward the rear wall 7, there is made available an aircolumn of ap roximately the aggregate length of the two orns while isapproximately of only the overall length of the main horn has to betaken into consideration in the mounting of the horn in a cabinnet. Theincreased air column. afiorded gives greater volume and truer tones.Harshness of tone is entirely eliminated. Overtones incident to"vibration of the material of the transmitting medium are avoided byproviding the horn entirely of wooden construction with the roper wallthicknesses, as above mentioned.

he sound originating at the small end of the secondary horn is reflectedat the back wall 7-of the main horn and the echo is trans mitted. Anopenin 16 is provided in the bottom wall 11, of the main horncommunieating with the small end of the secondary horn, as shown. A loudspeaker unit 17 of any one of the usual or preferred types is mounted atthe opening 16, as shown. A plate 18 for supporting the unit may besecured to the outside wall 11 at the opening it is believed that theforegoing descri tio'n conveys a clear understanding of t e inventionand-of its purposes and advantages so that anyone skilled in the art towhich 1 smal horn communicating with sihle applications thereof. v

I claima' 0 1. A horn of the-character described compridsa main hornhaving a bee wall an fverging side walls extending out wardly there rom,and a secondary horn within the main horn in reversed relation theretoso as to be directed toward the back wall thereof and having a side wallin common with the main horn, said wall having an o ening therethroughleading into the end of the secondary horn. Y 2. An amplifier horncomprising a :main horn having a back wall and diverging side wallsextending outwardly therefrom, and

Ya secondar horn built within said main horn in revers relation theretoso as tobe directed toward the back wall thereof, said seconda hornhaving one of its side walls formed y one of the .side walls of saidmain horn.

3. An amplifier horn comprising a main horn having a back wall anddiverging side walls extending outwardly therefrom, and a secondary horndisposed within saidmain horn on one side wall thereof and in reversedrelation thereto so/ as to be directed toward the back wall an openingin the side wall of said the small end of mam V said secondary horn toprovide a place ,for

v,on one of the 'side walls' thereof using said thereof, there beingmounting a re'producer unit transmitting into the small end of saidsecondary horn. 4. An amplifier horn comprising a main horn of atruncated bell form havin a back wall and diverging side walls exten ngout-v wardly therefrom, and a secondary horn b t onto one of the sidewalls of said 111 in horn usin said side wall as one of the side walls-osaid secondary horn, said secondary horn being reversed in relation tosaid main horn an directed toward the back wall thereof, the small endof said secondary horn being arranged to have communication with asourceo large small end of said main horn. 5. An amplifier horncomprisingla main .bell having a thick back wall and t walls diverginoutwardly therefrom, and a secondary be 1 built within said main bellwall as one of the walls of said secondar bell, said secondary bellhaving a'thick bac wall and thick diverging lateral walls, the-remaining wall being relatively ex ding with said lateral J OHAN O.BERGMAN.

sound, and the end thereof communicating with the.

ick side thin and walls in diver -i" relation from said last mentionedbac wal inwardly relative to said-main bell toward the back

